1. Field of the Invention
The present invention relates to a method and system for tracking the wearable life of an ophthalmic product.
2. Description of the Prior Art
The contact lens market in the United States is a multi-billion dollar market. Recent data indicate that nearly 36 million Americans—almost 13% of all Americans wear contact lenses. There are numerous manufacturers of contact lenses and many different channels of distribution, including eye care practitioners (e.g., ophthalmologists and optometrists), national and regional optical chains, mass merchants, and mail order and Internet firms. The contact lenses include any of the following basic types: soft, rigid gas permeable and hard. Soft contact lenses are made of a highly flexible material that contains water or silicone or hydrophilic hydrogels, oxygen can reach the eye when soft contacts are used. Rigid gas permeable contact lenses, frequently referred to as RGP contact lenses, are composed of a firm plastic material and do not contain water. RGP lenses permit oxygen to pass directly through the lens to the eye so that it may “breathe.” Because they transmit oxygen, these lenses are referred to as gas permeable. Hard contact lenses are made of a hard plastic material. Hard lenses, also called PMMA lenses, were the first mass-market contact lenses. Unlike RGP lenses, PMMA lenses do not allow oxygen to pass through the lens to the eye.
Contact lenses are often manufactured with identifying marks useful for indicating which contact lens goes into which eye, or indicating serial numbers, lot and batch numbers, and optical powers. The methods for providing identifying marks are well known in the machine tooling and contact lens field, for example, using a laser, electrical discharge, machining, mechanical scribing, diamond scribing, ultrasonic scribing, holographic marking, and scattering by surface disruption. These markings such as brand name, on the edge may help to identify between the right and left contact lenses.
In most countries, contact lenses are classified as medical devices, as such they are normally dispensed with only with a valid prescription from a qualified eyecare practitioner. For example, in the United States a contact lens is a FDA-regulated product. A valid prescription typically includes user's name, eye practitioner's name, contact lens brand name and material, lens measurements such as power, diameter and base curve, directions for safe use such as wearing schedule, whether lenses are for daily or extended wear, the number of refills, whether lens material substitutions are allowed and an expiration date. Also, since eyes change all the time, such prescriptions do not last forever, with most having an expiration date, and thus should be updated periodically. Each lens manufacturer has a replacement schedule of a contact lens, that is, how long the lenses can be safely worn before discarding. The replacement schedule depends on the manufacturer or the type of lens chosen.
For example, RGPs last several years, while soft contact lenses come in a wider variety of replacement schedules: daily disposable—1 day, disposable (extended wear)—1 week to 1 month, disposable (daily wear)—2 weeks, frequent replacement (also called “planned replacement”), 1 month to several months, depending on brand, conventional 1-year. Contact lenses are available for two different wear schedules: daily wear, meaning they should be removed before sleeping & extended wear, or overnight wear. Also, with planned-replacement lenses, an eye care practitioner works out a replacement schedule tailored to each user's needs. For example, for users who produce a higher level of protein in their eyes or don't take as good care of their lenses, it might be healthier to replace the lenses more frequently. Therefore, the onus to keep track of the wearable life of the lenses falls on the user. As such, if a user does not record the date of first use, as time passes it can become difficult to recall how long a particular pair of contact lenses has been worn.
Despite recommendations by eye care practitioners to replace lenses as specified in the prescriptions, most users continue to use these lens well past the expiration date or replacement date, whether unwittingly or otherwise. Such practices present a very serious safety concern with contact lenses. Extended-wear (overnight) contact lenses, rigid or soft, increase the risk of corneal ulcers, infection-caused eruptions on the cornea that can lead to blindness. Symptoms include vision changes, eye redness, eye discomfort or pain, and excessive tearing. Another sight-threatening concern is the infection Acanthamoeba keratitis, caused by improper lens care. This difficult-to-treat parasitic infection's symptoms are similar to those of corneal ulcers.
Several solutions have been presented in the prior art, however these solutions place the onus of tracking the day-to-day wear of the lenses on the user.
It is thus one of the objects of this invention to mitigate or obviate at least one of the aforementioned disadvantages.